1. Field of the Invention
The present invention is related to an omnidirectional antenna, in particular to the antenna including antenna units oppositely disposed on a grounded substrate for achieving omnidirectional radiation.
2. Description of Related Art
Antenna is an essential component for the various electronic devices for transmitting or receiving RF (radio frequency) signals. Antenna is introduced to converting electric power into radio waves for delivery over air. On the other hand, the antenna also converts the radio waves into the electronic signals. While the RF signals are delivered, a radio receiver or transmitter connected with the antenna in the device can convert the energy of radio waves to the signals applicable to the circuit of the device.
The antenna is configured to a specific application according to the required characteristics and performance. The performance specified to the antenna is usually the one of reasons the technical person selects the antenna.
One of the classes of antennas is such as an omnidirectional antenna that radiates radio wave power uniformly in all directions over a whole sky. One further class is such as a directional antenna that only processes the radio waves specified to or from a narrow range of directions. The any antenna may include a reflection unit and a pointing unit, or any plane for guiding the radio waves.